The study tests the effectiveness of singing interventions led by the Royal College of Music at Chelsea and Westminster Hospital as a psychosocial tool to reduce the occurrence and effects of postnatal depression. It triangulates psychological, physiological, and biological data in a randomised control design to provide a comprehensive insight into the intervention's effects in comparison to a more common psychosocial intervention for new mothers (play groups) and a control group of no psychosocial interventions. The study aims to recruit 50-80 women into each of the three interventions (150-240 total).